jiju1943

I am at the point now that I will need to replace the engine in our 1998 4Runner. The engine started off going south when the cam gear sheared the pin and snapped the bolt holding the gear on. I pulled the heads to see how the cylinders are and found I also have a blown head gasket. I just bought this truck and have never heard it run so I had no idea it had a blown head gasket.

When I pulled the valve covers off I knew from the heavy gunk on the heads that the motor had not be taken care of. I have the motor down the to block at this time. I read where I have to pull the wiring harness out to pull the engine, why do I have to do that, why can't I just leave the harness in place. I don't plan to pull the transmission, if that has anything to do with it.

Charchee

You don't. As a matter of fact, you will likely need your engine wiring for the new engine. Most of the engines, themselves are the same but the wiring can be different. Save all of your parts. You may need some of your sensors and odds and ends if your replacement engine is not from a very close year model machine.

I really don't know why someone would tell you that you have to pull the harness with the engine. It may be easier if you already knew the engine was bad to begin with but you already have most of the harness loose of the engine.

jiju1943

Thank you for letting me know I don't have to take the wiring harness out, I couldn't figure out why it had to come out. The engine is supposed to fit the 4Runner, they say it is a low mileage engine imported from Japan, I sure hope it is. Thanks again, I really appreciate your help.

Jim

Charchee

I've seen those adds a million times. I think they are good engines but be sure to check it over good and check compression before you go to the trouble of installing it.

jiju1943

That is a good idea, thanks again Charchee.

SacRunner

Just some friendly advice, be careful buying a Japanese motor for a 3.4 swap. Most people that buy those imported motors have to spend a bunch of time swapping parts from their existing 3.4 onto the Japanese 3.4; these motors typically come from a Hi-Ace mini-van and are setup very different than the 4Runner/Tacoma/T100s in the US market. You'll be at the disadvantage that you don't have a "donor" 3.4 to swap parts from to the Japanese motor.

Beyond that, you'll need the ECU and a matching harness at an absolute minimum, which I have heard do not come with JDM motors.

At any rate, welcome and good luck!

jiju1943

Wallace, I really appreciate the information, I really don't want any surprises.
I just looked at 2500 parts on Craigslist and found one engine, but they didn't have any contact information. I have been putting off pulling the block out of the runner, but once I do I will still check out the bottom end of the engine to see what is going on down there, I will make a decision then if I am going to rebuild or buy used. I really want to buy a good used engine but I am a little leery now.

I really do appreciate your help Wallace, your information is a huge help, thank you.

jiju1943

I got a question, why can't I just change out the plugs on the import engine with the ones on the old engine and use my old wiring harness, is that possible or is there something I don't know?